Actually, I think bluestripes - especially the females - are among the easiest pipes to keep in a smaller tank like yours. (In addition to mysis, mine will also eat frozen cyclopeeze.)
IF your tank is well established and IF there are no serious competitors (such as sixline wrasses, mandarins, scooter blennies, peppermint shrimp, etc.) for pods, they can do quite well surviving on what they forage in a 29. That's not to say that you shouldn't also feed them - you absolutely should. I just think their small size means that it's easier for them to do well even if it takes them awhile to eat frozen foods.
Paul may have a different view.
I would advise you not to listen to blanket statements like "bristle worms are bad." While there are a few rare exceptions, virtually all of the common types of bristle worms that show up in your tank are beneficial. An overpopulation is usually a sign of overfeeding.
BTW, the 20 gallon tank my bluestripe lives in relies on live rock for filtration. I have a HOB filter, but it's just got more live rock rubble in it. It was a little mini-fuge with a light an chaeto, but the light burned out and I haven't replaced it. The only other flow is from a little Maxijet 900.