Hiteffect.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class HitEffect : MonoBehaviour
{

    MaterialPropertyBlock props;

    Renderer[] renderers;
    //Animator anim; uncomment if you have an animator attached and a hit animation
    // Start is called before the first frame update
    void Start()
    {
        props = new MaterialPropertyBlock();
        renderers = transform.GetComponentsInChildren<Renderer>();
        // anim = GetComponent<Animator>(); uncomment if you have an animator attached and a hit animation

    }

    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.H))
        {
            // anim.Play("Hit"); uncomment if you have an animator attached and a hit animation
            StartCoroutine(HitShaderEffect());
        }
    }

    IEnumerator HitShaderEffect()
    {
        props.SetFloat("_Hit", 1f);
        for (int i = 0; i < renderers.Length; i++)
        {
            renderers[i].SetPropertyBlock(props);
        }
        yield return new WaitForSeconds(0.1f);
        props.SetFloat("_Hit", 0f);
        for (int i = 0; i < renderers.Length; i++)
        {
            renderers[i].SetPropertyBlock(props);
        }

    }
}