Any store with a plumbing supply dept. will have Rid-X and / or a number of enzyme treatments. These can help both the tank and the laterals.
One thing tho’ - if the ph of the tank is still way off, then the enzymes in the treatment may get zonked too. I’m not sure what the best solution is. MAYBE a tank that was too “base” could be treated with a substantial quantity of a mild acid, but, that might create hydrogen, so, be careful! Better would be to flush the system if possible, I would think. Or get it pumped out. (Septic systems need that periodically to remove undigestible solids.)
That all said, I’d just avoid the issue. I’d be willing to bet most any respiratory virus won’t last 30 minutes in a properly functioning septic system. (Very harsh environment if you’re not the right kind of “bug”.)
Correction: Depending on the type of bleach, an acid plus bleach can create chlorine gas. Might or might not get hydrogen depending on the type of acid. I assume the original question referred to chlorine based bleach - there are even acid based bleaches.
Further info. here:
https://www.quora.com/Is-bleach-an-acid-or-a-base
PH of a septic tank should be neutral. 6.5 - 7.5.
You don’t really have to add Rid-X or whatever after pumping, if the PH is ok once the tank refills: the “good bugs” should repopulate naturally, quickly. If the PH is not ok, the treatment probably gets “killed” too. Rid-X is most helpful if the septic system is marginally inadequate for the load placed on it. One of my wife’s friends likes to throw big parties, and her husband dumps in some Rid-X earlier that day. I’ve been occasionally putting some of the stuff that is geared toward eating paper in the lines @ my Mom’s, as she uses “craploads” of toilet tissue. Seems to help.
Boy, are we OT or what!
As with an aquarium, a large percentage change of water would probably help reduce chemical contaminants. Just don’t use chemicals that could dissolve any grease buildup and allow that to reach the leach field. Supplement with an anaerobic digesting bacteria.