I think it would be really difficult to use tongs for things like mysis. And obviously, if you end up feeding something like cyclopeeze, it would be impossible! I jerry-rigged a bent piece of airline tubing on the end of my turkey baster, so it works a little more precisely. When I feed the open brain bigger chunks, I just use chopsticks. lol. (Hey, I lived in Korea for a time, so I figured I should make good use of my acquired skills
)
The GBTA will eat mysis, silversides (cut up), or other pieces of raw shrimp/squid/etc. cut up so that it will fit inside its mouth. I'm not sure what sand polyps are, and I wouldn't personally attempt to spot feed the leather. The blasto and open brain will gobble up all the mysis or small meaty bits you can give it, as well as cyclopeeze.