[TFA] Fed up with Malaysian trumpet snails

I would really like to get rid of the population of MTS in my 29
gallon tank. Unfortunately when we set up the tank a year ago, somehow
an MTS snuck in on a plant or something. In the beginning I tried
picking them out but you can never get them all.

Lately, yes, I know I have been overfeeding algae wafers but I have a
bunch of growing young ancistrus that I want to make sure are getting
enough food. I introduced some assassin snails, which have done a good
job for me in other tanks eliminating pond snails and ramshorns, but
MTS are harder for them to eat. I was hoping since there weren't any
other kinds of snails, the assassins would go for the MTS. Instead
however they have been breeding (never bred in my other tanks that I
saw) so now I have tiny assassin snails mixed in with the tiny MTS.
When the baby assassins get big enough I'll take them to the LFS,
unless they start eating MTS.

I read that Spixie snails might eat MTS so I got three of those.  They
are pretty snails but I have yet to see them eat another snail, so I
suspect that's a myth and they actually just eat algae like most other
snails.

I'd consider some kind of loach if they would be compatible with my
other fish and actually would eat MTS. I have two adult ancistrus and
the babies, that are going to the LFS as soon as they are big enough,
some rummynose and glowlight tetras, and six hatchetfish. Clown
loaches get too big but is there anything else that would eat snails.
Maybe yoyo?

I've noticed I don't see MTS in my betta tanks so I wonder if some
bettas will eat the smaller MTS. I've never seen them do it, but some
of them, especially the females, spend a lot of time nipping at
anything they think might be edible so maybe they do eat small snails.

Any other ideas?
Thanks-
yngver