I don't know exactly what the chances of hitting 2pr better on the flop, but I think it's around the same odds, maybe a little less likely, as hitting a set with pockets, so perhaps around one in ten flops. I think the call of 30 with a one in ten chance to hit a flop hard means we need to have the potential for a profit of $3, which means their stacks and tendancies must make this possible, otherwise we can never justify a call, we're not priced in. With three others in the hand, the pot size potential is huge, so in this hand I can see 23s or 73s as an outside possibility, it cannot be disragarded, because I'd consider the call, I wouldn't snap fold like I would if it were a heads up pot against a short stack, for example.
Of course, trash like 23s has the ability to be punished badly by better flushes or, worse, paired boards. When it loses to a better flush, you accept it immediately, you know it's a danger, but it's the times you get in with your juicy 2pr on the flop against the overpair AA, the whole bloody point of calling the raise, and cry as the turn J and river J crush your feeble little hand. It happens a lot more often than having a flush beat.
Point of all that nonsense is, while sometimes it might make sense to make a call with 23s, the high pot potential has to be there, because the variance is high and you can lose your stack and vow to hunt OngBonga down for even putting the idea into your head that 23s is playable. Be prepared for a rollercoaster, but against the right people, in the right spots, 23s can make you money. Just be careful!