Just caught this thread and have two points to make.
1. If you decide to paint your inside teak, do yourself, any future owners of your boat and the world a favour and ensure it is well varnished first. This will seal the pores of the wood and prevent the paint from being drawn into the wood. Then, down the road, if you or a subsequent owner want the teak back you can strip the finish and have clean teak without having to sand it way down to get past the last bits of absorbed paint.
Offshore sailors do this on exterior teak sometimes for the weatherproofing of the paint and when they are back alongshore they can strip it back and return to varnish.
2. Spray Nine is great stuff but it's a caustic toxin - our dog ate a paper towel that had been used to wipe up S9 and he almost died - lost control of his whole back 1/2 before we got him to the vet. The antidote was to hook him up to an alcohol IV drip which acted as a solvent to flush it out of him. When we saw the vet pouring an airline bottle of Stoly into the drip we asked and he said it was just as good as lab alky but a fraction of the price. Next day the dog was hungover but fine and we had a good story.
Be careful with Spray Nine. I used ZEP purple degreaser from Home Depot for the same job - works great and it's sold as being "green"