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I had been vexed by some crud on 2 of my lenses, both Meade Series 4000 Plossls - the 9.7mm and the 26mm. I know some people can be fanatical about not cleaning lenses for fear of scratching or marring the lens or its coating, but these particles on my lenses were so distracting I felt I needed to clean them somehow.
Trying a tissue moistened with distilled water hadn't done much, nor did canned air or a "blower" bulb. I had yet to try isopropyl alcohol as I didn't have any to hand that was pure (I only had 70% rubbing alcohol in the house, which has other chemicals in it which might leave a residue).
Based on some comments in the USENET group sci.astro.amateur, I went out and picked up a gizmo called a LensPen MiniPro at the local Ritz camera for $7.99.
The LensPen has a retractable soft brush on one end, and a unique flexible cleaning tip on the other end. This cleaning tip, which is 7mm in diameter on the MiniPro and 15mm on the regular LensPen, uses a carbon-based cleaning compound to help get rid of smudges like fingerprints.
I'm very happy to say that the LensPen did a wonderful job on the lenses! The brush took off most of the particles, and almost all of rest easily came off with the cleaner tip. There was one relatively big particle that seemed particularly stubborn. I used my fingernail (gasp!) to dislodge it, then swept it off with the brush. Of course, I'd left a fingerprint on the lens. This came off in seconds with the cleaning tip, leaving me with a very clean eyepiece. No discernable flaws, marks or scratches were visible in the lens coating, and some terrestrial test views shows the lenses to be nice and clean. No residue from the cleaning tip was visible after use.
Eyepiece lenses seem to pick up a lot of dirt from sitting outside on the scope while it sits unused (soot? comet dust? Who knows?). This is not as big a problem with the main corrector lens on the ETX, likely thanks to my dew cap, so I haven't needed to do anything to that surface except brush a little dust off it.
I'm really happy with this little unit. It seems a lot safer and easier than using lens tissues or cloths on the eyepieces, and is very inexpensive. There is a website for the LensPen at http://www.lenspen.com/ but is not sold through that website. It seems widely distributed through photo stores, and is also available from Scopetronix.