I cleaned 64 pews (25 ft long) and all of the chairs for the choir for a church here in Plano, TX. I charged them $1 per linear foot.
They were happy with the results so I told them that I was going to estimate their carpet as well so that they could call me when they were ready to have it cleaned. While I was measuring, the pastor told me he wanted an estimate on another 130+ chairs. When I gave him those estimates, he asked me if I do residential cleaning and I cleaned his house 3 days later. I really like doing work for churches.