Sophia has a course on how to deal with deodorizing books. It's only 99 cents.
I would be really careful with the dryer sheets. (Before I explain why just feel the need to point out that I'm actually a costumer by trade that ended up with a library job. Long story, but that's where my real expertise is.) Dryer sheets are actually very thin pieces of fabric that are coated with fabric softener. If you rub an unused sheet between your fingers, you will be able to feel it. Then rub it between your fingers some more. Then set the sheet aside and rub your fingers together. Do you feel that stuff on your fingers? That's the fabric softener. Now do your best to ignore it, see how long you can go about your business before you feel the need to wash it off your hands, and you will have a pretty good idea of just how well this stuff sticks to things. That is what you are getting on your books if you are using dryer sheets on them.
Here is why this is a problem:
Lingerie experts (Yes, that's a thing. And yes, I giggled when I found out too.) will tell you not to wash your bras, panties, and other delicates with fabric softener in order to make your garments last longer. The reason why fabric softener works is that it very gently breaks down and weakens the fibers of your clothes. If you are washing very heavy duty fabric like denim, this doesn't really matter. But if you are washing something that is already delicate to begin with, you don't want to weaken the fibers even more.
So what do bras have to do with books? If you are trying to preserve something for a long time, you don't want to weaken the fibers. Adding a chemical whose whole purpose is to weaken fibers seems really risky to me. Plus if you have ever washed a load of clothes with fabric softener that didn't rinse well, you know that it's not coming out again until you wash it properly.
On a side note, watered-down fabric softener is a paper aging technique used in the theatre for prop creation. Yet another reason why putting it on a book makes me nervous.
As I previously stated, I'm a fabric person first and a book person second, but I would use Sophia's recommended techniques from her course. She has the expensive, framed papers on her wall. ;D