[JRTJH]

Many of us use that "garden hose cap" all the time in place of the 3" cap. If you've ever had a gray or "heaven forbid" black tank valve leak, then you've had to deal with a 3" gush of water as you remove the cap and try to stop the flow as you install the sewer hose fitting. NOT FUN !!!!!

With that cap in place, if the right "sewer storm" occurs, you can empty the accumulation by removing the 3/4" cap and allowing a "much easier flow of stuff" that you can easily contain in a bucket rather than a 3" gush that tends to splash all over you and anyone else that might be unlucky enough to be nearby …

I use that cap in place of the 3" cap all the time.