I tried to post a link from the state of Alabama but curezone won't let me. I'll summarize. It basically said they weren't certain but it appears as though H2O2 (Hydrogen-Peroxid) will help clear lateral lines but not to put it in the actual tank (probably because it's not as useful there). Add it to the lines. Also, the recommended rate is 1% per square foot of leach field area. I would think the 35 would be better. You'll get more bang out of it, and have a higher concentration, but still a lot more dilute then what they suggest. By their calculations it would require an extremely large quantity of H2o2. I used 4 gallons in my lines which wouldn't even be 10% of what they are recommending. But it turned my dark grey effluent to almost clear overnight. I would imagine it cleaned out the lines pretty well too. I also don't think you need to wait 3-4 weeks. I would imagine a week at the most and you'll be good to go.