Drive Through Cleaner - Do you tip?

[WNDMom]

I just started using a drive through cleaner, and I'm not sure the appropriate amount to tip. Do you tip? A flat amount or percentage?

 

[SwedishMeatball]

I go inside and don't tip. If I used a drive through I still wouldn't. Now my neighbor leaves her laundry on the porch for pick up and it's delivered that afternoon. In that case, I would consider it.