The first process is the short process in which the degreasing and coating are made in the same bath. It is suitable for low-grease surfaces and more practical. It takes a small space.
The second process should be preferred if there are more greasy surfaces. Thus, the coating bath does not get dirty quickly and has longer bath life.
Yes it is possible. However, it needs to be changed more quickly than the process with rinsing. Because when the bath is soiled, there will not be a rinse to clean the impurities that are likely to remain on it.