Make a part collidable with certain parts?

How would i be able to make a part collidable with certain parts, but not with others? (Without turning CanCollide to true and false over and over again)

You may get mad for this, but that's the way.

You can create a part that is originally collidable, and make ones with certain names stop.

Let's give an example.

local name1="ball"
local name2="duck"
function touch(hit)
if hit.Name~=name1 or name2 then
script.Parent.CanCollide=false
wait(.5)
script.Parent.CanCollide=true
else
ex=Instance.new("Explosion")
ex.Parent=game.Workspace
ex.Position=script.Parent.Position
end
end
Script.Parent.Touched:connect(touch)

This will let any part without the name duck or ball through. If not, BOOM!

Hope this helped!

-ds