Dimensions: 30″ x 12″ x 18″ (76.2 cm x 30.48 cm x 45.72 cm)So, I'm not familiar with the dimensions of a 23g, can you tell us again please?
All of your fish would like to be kept in larger numbers; 6 as a minimum for all your species; more would be better!...if there's tank space...but there might not be...floor space for bottom feeders (corys)? Side to side for schooling tetras?...otos? They're kind of delicate in a fussy feeding "on the glass" kind of way. All "can" be kept in a smaller tank...with the right balance...
ok so loaches are out lol more cory's and oto's it is!! looks like bladder snails, and I just found a different one today... Not sure what kind.. might be a ram horn.NO!! Don't get (my favs) loaches to deal with a snail issue. They, like all your fish choices, would like to be kept in a minimum of 6. They, as all your fish, behave much more "normally" in bigger groups. Choose either 6-8 corys OR dwarf loaches...you don't have room for both.
We're trying to help you have balanced tank for the longer term. Think hard...if you can only have 3 species, which 3 will you choose? The biggest issue I see are dwarf loaches vs corys. Pick 1 of those 2.
What kind of snails are you worried about? I like a few...but they may need control...