I bought a special cleaning kit
https://www.amazon.co.uk/gp/product/B071DG5XZR/?tag=
For one thing, and one thing only: That plastic scoop/sieve thingy. Trying to pick dozens of MTS out of sand is crazy difficult and annoying, so I hoped that sieve thing would work, and it does! I scoop, sand falls through, large enough snails get trapped and lifted out. And it's pretty fine, so it gets them when they're quite small.
I should feed less to try to stop them breeding so much, but with baby fish, cories and shrimp, tank needs pretty heavy feeding, and the snails set upon anything put in for the cories or shrimp. I like MTS, I appreciate them burrowing the sand for me, but there's way too many of them and I think they're eating my plants too.