Put them into a plastic cup with tank water. When you removed them try not to get them exposed to air. Like hold the cup under water while dropping in the eggs. No air stone is needed. Put them in a dark quiet place and wait 4 to 5 days. Then put the hatched fry into a fry saver in the parents tank until they are large enough not to be considered food anymore. The fry won't all hatch on the same day but you have to remove the hatched ones each day. I waited once until all of them hatched only to find the water fouled and all fry were dead. Once they start hatching the water in the cup should be partially changed each day to prevent this from happening. You could also put the hatched corys into the BN tank with BN fry but adult BNs might accidentally hurt them by just waltzing over them in such a small tank.
BTW MTSs clone themselves and do not lay eggs.
BTW MTSs clone themselves and do not lay eggs.