Monoperoxywhatcamacallit is non chlorine shock, it is a very powerful oxidizer. Some people (like me) use it to shock their hot tub, others use chlorine (dichlor) and some use a lithium based shock. You should not have any in your water as it gets used up almost immediately after adding it.
You are probably way overdue
for a water change seeing that it has been since March. Most folks will change their water about every 3 months or so. You could have your dealer test you water for TDS (total dissolved solids) once a month and when the number reaches about 1500 you will know its time to change the water
If it bothers your husbands knees to get down and hook up the drains try using a small submersible pump to drain your tub. I bought one at Home Depot for about $100 and it is much easier and faster then the drain at the bottom of my tub
Sorry you can't find someone to do this for you, maybe a neighborhood teenager could be some help. I know my nephew will do just about anything for food
