I have a 10 gallon tropical tank semi-barebottom with some small snails and one very mellow male betta aka Joker. He's so mellow he'll let me pick him up *with my bare hands* when I do waterchanges and put him in his bucket.

Could I introduce something like a Clown Loach into this tank? I've always wanted one but I only have the one tropical tank. I also want some kind of tank-mate for my Joker-fish

Thanks, guys.

Clown Loaches need a large tank as they grow really big. Ive seen one at my store thats around 8 inches long and a girth of around 5 inches, so pretty big. They take a few years to get to that size but need a minimum tank size when small of 20 gallons and need to be kept in pairs or a small group. Of course as it grows it will need further upgrades in tank size.
What about corydoras cats? These stay relatively small and you can get the pygmy kind. You could easily get 3 of those for the tank.
Hope that helped

Clown loaches won't work in a 10g, though it takes them are very long time to reach a giant size they do grow very large. Sandy is right, you should look into some corydoras, there are many small species that save the same purpose and are equally entertaining.