Bubba and I talked about things a little more today and proposed the following path forward to Michael L.:
1. Place cleanrooms over both BSC3 and BSC2
2. Pull domes from both chambers
3. Remove east door from BSC3
4. Remove optics from BSC3-->BSC2-->BSC1 and "cake tin" them as close to the chamber as possible
5. Install dust barrier between BSC1 and BSC2 
6. Remove "guts" from BSC2-->BSC3
7. Chamber clean BSC2
8. Install dust barrier between BSC2 and BSC3
9. Chamber clean BSC3
10.Return domes and door
We have enough cleanrooms to accommodate the proposal and that way we won't be tromping through cleaned chambers.