Press ctrl + d to bookmark this page for later or tell your friends about it with. This will be useful someday i never knew the pepsi method, will have to try that out if and when my drain gets clogged in the future! If pressure has dropped once, it will drop again. We are there when you need us most even on nights & weekends we have our plumbing technicians on-call 24 hours a day and 7 days a week. If you're a landlord, we offer. In any major debacle involving your plumbing,.