How do I make a lightsaber cutting/melting effect?

I've seen it in many roblox lightsaber games, you swing across the wall with a lightsaber and it leaves a glowing stripe on the wall. I've been working on making my own lightsabers lately and wanted to add this effect too, I have tried a few methods of me but they worked out really ugly or not working.

One of my ideas was making small parts in a row along the blade with in every part a script that would enable a particle effect on Touch and and disable it on TouchEnded. When I tried some parts in the blade didn't stop the melting effect. To conclude: using Touch events didn't seem like an option.

btw here is the script I used if interested:

local melt = script.Parent.MeltParticle

script.Parent.Touched:Connect(function(hit)
	if hit.Name ~= "Blade" then
		if hit.Material == Enum.Material.Concrete then
			melt.Enabled = true
		end
		if hit.Material == Enum.Material.Air then
			melt.Enabled = false
		end
	end
end)

script.Parent.TouchEnded:Connect(function(hit)
	if hit.Name ~= "Blade" then
		melt.Enabled = false
	end
end)

Does anyone know how they did that in those games?