Daily Adjusted Seatpost for Trainer Bike I just got Nashbar's Ascent Fluid trainer and put an old big-box store bike on it that nobody was using, so now I've got kind of a permanent trainer bike which is nice.

The problem: me and my partner are different heights/sizes, though close enough that all I really want to do is raise the seatpost when I ride, then adjust back down when I'm done. 

Of course I need a new seatpost for this b/c it's too short to go any higher.

My question: is there a risk of damaging/wearing out the seatpost/tube quickly by adjusting it twice daily (once when I get on, then again when I get off)? 

If so, what kind of lube (if that's suggested) should I use that won't have toxic/smelly fumes and be excessively messy/require wipedown every time I lower the seatpost?

I use park anti-sieze for my main ride, but that stuff is nasty/toxic so I don't leave any exposed (on the rare occasion I adjust height).

Should I just resign myself to eventually wearing out the seat tube and/or buying new cheapo seatposts once in a while?
Just buy an inexpensive metal seat post, and if eventually it wears out it wears out. That seems to be your least expensive option. Especially if it's just a trainer bike.

Just lube it up with either a little bit of oil or odorless teflon grease.