Does anyone know of such a service in the DC/Maryland area?

ff, you might like to try to get ahold of Charlie Jean (envirogirl).  She had a friend that was looking into setting up such a business.  Don't know if that person ever "got it off the ground", though.

Another fine choice for this service is Miss Vanica.

I would totally be down for that.  I wonder if it could also be full service cleaning.

Forb, what are you looking for?  Maybe a flush and drain?