nah all he needs is sand, crickets and water. i use the red reptile sand cause i reckon it looks nicer. Maybe some leaf litter if you must decorate but be sure to cook/steralise it before placing with your swimmer. And it dont really matter if you give him too many crix in one go because he'll just dive under the sand when he's full so the extra crix wont annoy him at all.
After watching mine eat, it looks to me like the sand that gets on his tongue from lunging at crix he seems to scrape most off with his lips. Which ends up looking like he's got a sand mo! He then scrapes that off on the glass or goes for a swim. Probably still swallows a bit but dosent seem to bother them at all
Awesome litte characters, mine knows the sound of a cricket tub opening and comes out nearly standing on his back legs begging! its so cool, he enjoys the odd silkworm and mealworn too but mainly crickets