Hi,
Thank you for the comment. I have printed on watercolor sheets but you should know what separates it from the rest, understanding your medium is an important part of printmaking because a lot of factors depend on whether the sheet is going to work or not. The main difference is in paper density or grammage, generally you should use a paper quality that accentuates your artwork; they should both work together. Watercolor paper has much grater density than your average paper since it needs to hold moisture, the same can go with printmaking paper but not entirely. If you're working with techniques that need the paper to be soaked, like for instance if your working in intaglio or aquatints, then you need something that can stand all that moisture after that you test the pigment your using whether it merges well or not.
When I work in etchings I make it a habit to lightly feel the print once it's out of the press because intaglio gives an impression that doesn't necessarily come up in all papers. That's why you should look for something mid range unless you're experimenting. Somersets or Reeves are by far the best printmaking papers I've used but occasionally I'd find some random sheets in some store that would be even better (and much cheaper!).
I make it a habit to not buy paper that's been solely designed for watercolors or printmaking, instead I'd just go to stores and ask for sample sheets dip them in some water, bite into them check the burr of the paper. If the sheet gives a nice thick deckled edge when you tear it then it means the paper is of above average density and should be pretty good for printing on. Watercolor paper can do the trick but you should be careful of grain. There is a certain kind of grain that is associated with a lot of watercolor sheets, if that doesn't harm your image then you can certainly use them.
I should also point out that it's all about trial and error, you learn from the medium a lot in printmaking so remember not all heavy density papers will be good for printing. Similarly if you're working on hand burnishing you should probably stick to lighter sheets. Oil based inks will work on either.
Hope that helped