Unfortunately, the conversion process is slowed not only by measurable Baquacil (PHMB) but all the PHMB residue that's still present, but that you can't test!

The conversion info is here:
http://pool9.net/phmb/

Once you've started, you're pretty much committed to continuing to the end.

Trying to clean up algae and PHMB is not ideal. Odds are you're going to plug your filter before you're done. I'd recommend that you

+ put the filter on "recirculate" (= bypass filter) and run it 24/7.
+ Get a cheap oto kit, and begin dosing your pool with 3 gallons of PLAIN 8% household bleach EACH evening.
+ Test with OTO before adding a dose; skip the dose of you get a DARK yellow (or orange) OTO result.
+ Once all the algae is dead, begin testing in the AM, too.
+ Once your chlorine 'holds' overnight, turn OFF the pump -- but continue dosing.
+ Wait 24 - 48 hours (while maintaining chlorine!) and see if the algae and 'goo' will settle.
+ If it does, vacuum to waste.
+ Then resume circulating, but put the filter on "FILTER", and try to remove what's left.
+ Once the pool is clear, and chlorine holds overnight (test with the K2006), replace the sand in your filter.

You *may* have to replace the sand twice, if it's already totally gummed up.

Good luck!