I also think that you will be better of investing in a used macro lens, but here is a link to how different macro adapters will work with different lenses
Right, but there is no harm really in picking up a reverse ring considering they shouldn't cost more than 10 bucks. brand doesn't matter, just has to be f mount. I'd say go for it and see how it works for you, if you need something more then yeah maybe go for a macro lens, but if you are just fooling around, definitely try this (or extension tubes) first.
One of the complaints about the reverse rings and off brand extension tubes are the metering problems. However in the digital age, who cares! take a few test pics until you get your exposure right and there you go.
I use extension tubes on my old ftn and I love it, the ability to change them out and add more easily is great, whereas you aren't going to have that with the reverse adapter. Also I'd rather not put the inner part of my lens out there (I don't know the technical name for the back end of the lens glass, haha), so that's why I'd suggest extension tubes instead.