Just to note - sometimes it is easier to add something than remove it later. Maybe test on an old scope or one you were going to put up for sale (suitably described)…. Connor will be along to moderate that!
Some US friends (hunting types who enjoy the wilds) recommended "Clarity Defog it" wipes which are re-useable. Quite cheap in the US but extortionate on .co.uk for your major on-line shopping site. If you have someone in the US who can send some you will save a lot, but still the lens needs to be spotless before you apply the wipe. Supposed to last several weeks.
I have a pack of 3 but haven't used them - I just use a Rocket Blower!
BFTA Secretary 2012-2014
CSFTA Secretary 2014-2016