Oh I do sympathize ChillGill , I get presented with lots of pictures, glittery offerings, egg box robots and everything in between by my 3 DGC too.
My solution is that I have a secret box. It sits on display up on a high shelf on the top of my dresser . They can't reach it but they see me putting things in it. They often ask if they can look in and I say "oh dear me no. It's a secret box. if I were to let you look in, things might disappear" I have told them that each of them can look in when they are 18 . It seems to work and they think (or do they?) that all of their offerings are in that box! Mind you lots of things really are too precious to throw out (like letters, special pictures etc) but you really can't keep everything can you ?