I've attended several rituals where requests were made verbally and parchment wasn't used at all. In fact, I don't think I've ever attended a ritual where requests were burned. If you're worried about smell, you can always go that route. Or ritualize outside where smell won't be that big a factor.
If you want to conserve the parchment, you can always cut it into smaller pieces depending on how descriptive you get with your request.
..., and do I get to keep it and use it for various Rituals?
I suppose you could, but it seems like keeping it would effect the emotional purge you're trying to achieve. (Assuming I've understood your question.)