RE: Acetone Wash/Purifying MXE
I hope this write-up helps:

Disclaimer: I have never tried this procedures per se I'm just making an educated guess on the chemical properties of Methoxetamine.HCl and want to communicate the lab technics first and foremost.

There are three major ways you can purify your MXE:
1) Washing (easiest, least time consuming, may lead to losses, least effective)
2) Recrystallizing (moderately difficult, moderately time consuming, may lead to losses, generally effective)
3) Acid/Base extraction (few losses, moderate difficulty and time, effective towards non-polar impurities)

1) Let's start with washing:
You'll need a solvent that doesn't dissolve your product at all. Acetone at room temperature or slightly chilled in the freezer will work fine. Other usable solvents: Diethylether, chilled Methanol. Since MXE dissolves very well in water you need to dry your solvent of choice with a drying agent. Possible drying agents include: Sodium sulphate, magnesium sulphate (epsom salt) and calcium chloride. They need to be water-free, if you can't get your hands on water-free drying agent dry the powder for at least 4 hours at 200°C in the oven. Add a big spoon or 2 to each liter of solvent you want to dry. Stir for a few minutes and let sit for at least 10 minutes. Let all the drying agent settle and pour off your dried solvent into a clean, dry flask/glass/bottle. Now for the washing, disperse your powder and grind it up a bit if there are some bigger rocks in there to increase the surface area of the solvent. Pour about 30ml of solvent per gram of product and stir for 10-20 minutes. Let all the crystals settle and decant off your solvent or filter it (coffee filters work fairly well.). Let the powder dry (best on a flat dish for maximum surface area) and if you're curious on the impurities let the solvent evaporate in a well ventilated place for a few hours/days. You could even try to recuperate some of your losses by treating that residue with a much smaller amount of solvent to see if it all dissolves or if it leaves chunks of undissolved material (possibly product). Scrape up your goodies and you're good to go.

2) Recrystallization:
One of the most asked for maneuvres on the internet, I'll try my best for a comprehensive summary. The whole idea is basically the same as with washing only that you even get to the impurities trapped inside the crystals. This is done by dissolving the product in the minimal amount of solvent (boiling solvent) and letting it precipitate again when cooled and/or treated with another solvent. I also strongly recommend using the dried solvents as prepared in Step 1) for this procedure. Recrystallization for MXE hasn't been mentioned much in literature and I'm not so sure which solvent suits this best. Acetone is a feasible candidate as well as methanol, ethanol (everclear as high as you can get, and dry it), ether-methanol, or a small amount of pure IPA. You need some kind of beaker and a heat bath (water bath, oil bath). Add your MXE.HCl to the beaker and top it off with 5ml of Acetone, start stirring and heating until the Acetone starts boiling. If a lot of the MXE still hasn't dissolved add another 2ml Acetone and wait for it to bubble once more. Continue this until all the powder has dissolved and you have a clear solution. Now there are 2 ways to continue, the first is the classic and slow way and the second is faster but easier. The first would be turning of the heat bath letting the beaker slowly reach room temperature without applying cooling from outside. After that a few crystals should've already sprung into life; now close it and put in the freezer overnight. You can filter off the crystals the next day and wash them with small amounts of -10°C dry acetone. The second way would be precipitation by addition of a non-polar solvent. You would have to take the clear acetone-MXE solution and add at least the fivefold amount of Ether or Naphtha to the solution. Now cool it in an ice-bath or in a bucket of cold water and once it's cooled to about 5°C you can filter off the crystals and wash them again with -10°C dry acetone for final purification.
The remaining solvent from recrystallization can be evaporated and the residue recrystallized again or just evaporate half of the solution and put it in the freezer again to see if more MXE.HCl precipitates.

3) For impurities without Amine/Acid functionality: Dissolve your MXE.HCl in water. Add 100 ml Naphtha or Ether, and stir for a while. Seperate the layers and discard the organic phase. Basify the aqueous phase by slowly adding 2N NaOH (can be excess) at room-temperature. An oil should settle to the bottom or rise to the top. Add a small amount of non-polar solvent (Dichloromethane, Chloroform, Ether, Ethylacetate, Toluene) and stir or shake in a speration funnel and separate the layers. When using Ether, Ethylacetate and Toluene the top layer will be the organic layer (contains your MXE) and the bottom layer will be the aqueous. When using Chloroform and Dichloromethane it's the exact opposite. Do this at least 3 times with at least 30ml solvent. Combine all organic layers and wash them twice with water and brine (Sodium chloride solution). Now dry the solvent like mentioned in Step 1) and either gas HCl through the solution (more equipment needed, PM me for info) or add concentrated aqueous HCl dropwise until no more salt precipitates. The latter option is not optimal because quite a bit of the product will dissolve in the small amount of water added, you could gather those few milliliters of water and let it evaporate on a flat dish to harvest all your earnings.

I would advice using 1) first as it has been known for a while that a common impurity of MXE: [1-(ethylamino)cyclopentyl](3-methoxyphenyl)methanone, can be seperated this way.