Love the bean pic! Haha I bet it stinks but makes me wanna do it more for the humiliation hehe I'd probably spend hours in it. Even longer if I wasn't alone
The couple of times I've got messy involving beans (well short of a bath worth), I feel like they're one of my least favourite WAM substances. It's not even the smell so much as the texture, straight out of the can they're thin liquid with firm lumps in, and I like things with more of a thick, gloopy consistency.
A baked beans bath is my dream messy scenario, while I've never done one (yet) I've often thought about it. If I choose to do it, I'll probably use my spare room as the messy area, fill a 6ft inflatable pool with beans (seems more practical then filling an actual bath), making sure that the area is protected with plastic sheeting and the pool is linned with sheeting, and have a walk way to my bathroom, also protected with sheeting.
Like someone has said, I'd want to get a few sessions out of it so I'd try to find a way of keeping the beans from going off (maybe create an air tight seal on the top of the pool with tape and plastic sheeting?)
Now the tricky part, the actual filling of the pool and disposal of the beans. I haven't actually calculated the exact amount of tins needed for a filled pool but I think 200-300 regular size tins or 30-40 catering size tins sounds generous enough.
The disposal might be tedious but if timed right you could probably fill 2-3 bin bags with beans and put them in the general waste bin a day before collection. The rest should be ok to flush down the loo a bit at a time.
My one time in a bath of beans was great fun. See the pics on my profle. I'd love to do it again. I would also love to sit in a gunge tank with it full of beans too