ive never used dr zymes wasnt sure.
citric will prevent, it will not kill whats already there though. will stall it a bit though. It can kill and remove PM very well though.
Once you start a citric based regiment you need to finish the season with it imho. If you stop during flower youll usually have more issues then if you never did it to begin with because citric will oxidize and break down in time into elements fungi can actually feed off. Its not the chemical itself doing the work, its the surface PH change it causes. IIRC plants will even slowly absorb it. even in the root systems.
New sprayings will prevent it from spreading as quick but its probably not going to totally disappear. It will slow it down though. Citric acid is the only thing i know of that can stop bud rot from happening all together. But it doesnt always totally work, and if you drop the regiment for a bit youve def made a mistake to learn from lol. It has to be preemptive and kept up with after every time its washed from the plant or enough time and morning dewings have gone by.
Dont write off morning dew at this time of year, its on often overlooked encourager of PM and botrytis, especially in stretches of cloudy weather. Doesnt even have to rain.