I have a second customer that wants 3000 sq/ft of driveway cleaned and water base sealed. The first one didn’t need post treating.
It occurred to me I may need to post treat for any stripes, those of you that seal do you just come back the next day, rinse and seal? I don’t think dried SH and sealer mix too well.
I post treat maybe 20% of the time and I have sealed over post treat with out any problems. I post treat with just downstreamed house wash mix so it’s not very strong. If you rinse your post treat you’ll have to wait for it to try to seal
You definitely want to rinse off the salt if you’re sealing the driveway.
If I’m sealing a driveway and it’s really dirty I’ll do a strong pre-treat (because a post treat isn’t an option), then I’ll spray a light oxalic coat to bring the pH level down and then rinse the oxalic before it dries. I will also spend extra time cleaning it so there aren’t any stripes.
If it’s not that dirty, then I use normal Hw mix on it, clean it, spend a little extra time to avoid / get rid of striping, no post treat, then seal it.
Note: They sell pH pencils for concrete. You draw a line on the concrete and it leaves a color indicating the pH. Pretty cool.
We’ve never post-treated anything, so I can’t answer the specific question. Why not just do it so you don’t need to post-treat, get the check and get out of dodge? You definitely do not want the salt left.
We very rarely seal same day as wash (esp. something large), and only if it’s a travel issue. Most products who say you can, seem to be way less forgiving to work with, and have been the cause of the few major issues that we’ve had
Better said than done man. Stripes happen, no matter your method. I had a driveway earlier this year that was overshadowed by a tree, and the sheer volume of lichens was shocking. I also had a white painted drive and it looked like a checkerboard after I got done. Post treating cleaned it up.
I get a really high quality water base sealer that soaks right in to the concrete so it can be done the same day.
IDK, others may have different experience, but the super-high quality supplier we work with refuses to endorse ever sealing same day. They have one product that technically allows it, but they definitely do not recommend.
Lichen may be another story, as we don’t usually see anything that bad on concrete (and certainly not from anyone who cares enough to seal the surface). But I don’t think we’ve ever had a callback for streaky concrete that I can recall, and we’ve never post-treated. 
Pre-treat, neutralize (if sensitive plants in runoff area), SC, rinse. I’ve told a few of our guys a post-treat is an option if they have a concern, but as far as I know it’s never been done. Definitely would help you out in this case if it can be done without one.
Break out the 12v for the pretreat. Do not seal over stripes or post treat. Post treating stripes just makes stripes invisible, not removed. If you must post treat then run sc again to remove all contaminants. @qons had a great suggestion about neutralizing. Although I dont seal. I leave that for the guys that seal. Ive seen bad seal jobs and dont want one of them to be mine. It also requires different regulatory aspects here in Florida
