You'll need the following:
Can of "dust off" compressed gas
box of plain white brand name, Kleenex tissues
brand name "windex"
bottle of pure acetone.
The procedure is: blast the element with dust off to remove any grit, be careful first purge the spray and avoid tipping the can to avoid spraying fluid onto the element.
spray windex onto the tissue, wipe the element. one ( gentle) wipe, one tissue. tissues are cheap, lenses are expensive.
purge any debris with dust off
if clean stop now.
if not dampen tissue with acetone, one wipe one tissue, quickly follow up with a second dry tissue to clear any evaporation marks before they dry.
blast any debris with dust off.
if it's still not clean, then possibly try isopropyl alcohol in the same manner as acetone.
if still not clean...the coatings are likely etched/damaged ..... Ajax is not recommended
