It would be great to get up close and personal with Blackwater Falls. Unfortunately the park does not allow you to get close enough to do so.
The falls are relatively high so I guess they are afraid that people would jump/fall off of the top on to the rocks below.
However that part of the country has plenty of other falls and rivers where you can jump in and get wet.
I used to be involved with a church camp in SW PA before I moved to Indiana (and even for several years afterwards, but the logistics got to be too much.) I started going there as a camper in the 70's and kept going back every year for a week or 2 (or 3), as a volunteer counselor or dean (event leader) through 2003. I even met my wife there in 1994.
We took kids rock climbing, rappelling, caving, white water rafting, etc. Here is a page on the camp's website that has a few photos of the 'bumslides' in Ohiopyle State Park. http://jumonville.gospelcom.net/f/adv/bum%20slides/jv.f.adv.bs.html
With Jr and Sr High kids, the bumslides were not exactly relaxing.
But there are several pools along the slide that are a bit like a natural whirlpool as well as a 4 foot waterfall downstream a bit. The next valley over has a 40' waterfall that is only about 4' wide so you could get your massage there for sure.
Here is another breathtaking area in western PA: http://www.visitlawrencecounty.com/mcconnells_mills_state_park.asp
I grew up a few miles from there, and whenever I go back I try to stop there. It is my 'spiritual home'