The biggest benefit of bringing your own water on storefront or any job is saving time.
Many time saving techniques can be key to get you in and out faster bringing down wasted time spent on jobs.
It’s ideal to spend as much time washing as possible.
Eliminate checking in/out, getting water, invoicing/getting paid (at each time of service) possibly monthly, quarterly billing when possible.
Anything that gets you in and out and washing the next job.