The discussion about draining, in Worst pool yet? Can I get this clean?, became too technical for the Algae - Prevention and Treatment area, so it has been moved here. JasonLion
Chemically cleaning that pool is possible and all of the cautions mentioned should be heeded, however if we had to clean up that pool, we would hook a vac to hold the liner in place while the pool was drained and get out the soap and water. You would be done in a day instead of weeks. Half the water is already drained. If its a sand bottom rather than vermiculite, you would need to be more cautious in your cleaning process.