If your snare has lost its edginess it could be the result of a crack in the shell or damage to the bearing edge and/or snare beds. Remove both heads and perform a close inspection. If you see anything out of the ordinary, take the shell to your local drum repair person. Don’t try to fix it yourself. It’s easy to do even further damage. (But if you’re determined to try fixing it at home, here is a DIY way to repair a cracked shell.)
Before you reinstall hoops and tension rods, wipe down the inside with a dry cloth to remove any wood shavings or dust. (How does that stuff even get in there in the first place?) And make sure that all inner hardware bolts are tight to eliminate rattling.
I actually like for my tension rods to contact some friction as they are screwed into the lug, since it helps them to hold their tuning. But if you prefer your rods to feel smooth during tuning, take a few minutes to wipe them down with rubbing alcohol to remove the gunk. Make sure that every tension rod has a washer installed between it and the hoop, since they also help maintain the tension.
Duh! But as long as you’re at it, try changing both the batter and snare-side heads. Even though a stick might never touch the snare-side (or at least it shouldn’t), the ultra-thin film continues to stretch and deform over time as a result of tuning and intense vibration. If you haven’t changed the head for a while, you’ll be surprised what a difference it will make.
Since you already removed the snare-side head, you might as well go the distance and dress up your drum with a whole new set of snare wires. There are so many different models to choose from these days that you can really fine-tune your sound.