It is decades since I last went to Riga, but I well remember that the civvie girls were seriously hot, and dressed very attractively (it was summer). But unfortunately I think the working girls realised that they could earn much more abroad than they could working at home, so the local scene died off. Riga did gain a bit of a reputation at one time as a stag-do destination, but the authorities put their foot down. I would be surprised if you couldn't find a few strip joints, but equally I wouldn't be surprised if they are priced to fleece foreign fools.
I visited a couple of times, but gave up as Prague has far more to offer both the tourist and the punter.