I too am going to throw my weight behind the "drain, clean, refill" vs SLAM. Not sure what you pay for water but here in the midwest my 15,000 gallons was $100 (including wastewater charges, would be cheaper if you have a second meter or your city allows a one-time exemption for pool fills). Even if your water is twice what I pay, that's still only $100. If you have similar rates to me and can get a wastewater exception, that could be as little as $25. Drain, clean, refill, done. SLAM will work, but it will likely cost you the same and take a minimum of a week, if not longer. As mentioned, Intex pools are the only pool that can reliably be fully drained and cleaned. Nearly all other types of pools cannot be completely drained like this.
Also in the future if you ever have electrical or plumbing issues that prevent running your pump, you can add liquid chlorine by pouring it around the outside of the pool (to spread it out), then vigorously brushing your pool to mix it in.