Thanks butterfly mum
bigarse1 I made a weighted blanket by sewing two cotbed sheets together in a grid pattern and filling the spaces with uncooked rice. (Like Making a duvet but with rice instead of feathers). A dressmaker could probably run up something similar and if you used a shower curtain instead of sheets it could be wiped clean. Those weighted vests and blankets are so expensive.
We got a second hand inflated birth pool for a £10 on eBay and filled with balls to make a cheap ball pool that could take a fair amount of abuse from a trashing child.
For a while we used a travel cot with a jersey sheet stretched across the top and pulled down under the feet, to make a cocoon for him to lie and trash about in. He loved when we put another elasticated cot sheet across the top and he was all closed in!
Not sure if any of those ideas are useful.