One of the best “toys” from my childhood was that good, old fashioned can of Silly String.
For those that have never seen it then you should try to find some, assuming it is still manufactured. Nothing like a good point blank blast to the face of an un-suspecting target and the joyous fun of being a child who could seemingly make a mess and then clean it right up without fear of retribution from irritated adults.
I am sure that nowadays this type of toy would be considered dangerous and there was probably some lawsuit somewhere to lessen the likelihood of fun for others. Just be sure if you find some, you get a few good shots in at a litigious lawyer type. I bet you will feel good for doing so.