For MP, I have not try it before as I do not have the time to go to the market to buy and the time to take it out frm the fridge and thaw them.

From my fellow aro-keeper friend's experience,:-
1)starve yr aro - subjective. depending on yr aro. But mostly, they hv to starve them.
2)it is important to buy fresh MP.
3)some just buy and keep in the fridge.
4)some cleans them before keeping it in the fridge.
5)remember to remove the head, shell, legs or any sharp body parts of the MP. This is to prevent PA (protuding anus).
6)make sure to remove the MP if yr aro doesn't eat them as this will make yr water unhealthy for yr aro. But if you hv tankmates that can clean up the mess, well just leave it to them.

Hope this can clarify some of yr doubts.

Cheers.