Using Iodine on "suspicious" skin spots, a well as FBD areas

I'm sure this has been asked a bunch of times, but I searched on the topic and I'm still unsure about what is the recommended method for using Iodine (I've got Lugol's 5%) on skin spots that look sort of suspicious. My hunch is old sun damage, possibly pre-cancerous. I've had some little crusty spots pop up on my back the past couple years, they've gotten a little itchy, and I just noticed a few weeks ago that they're turning from light pink to brown. Yikes. I have been trying different things on and off, castor oil mixed with living clay, a diluted bloodroot bodywash from one of the curezone sponsers (crazy expensive, I can't keep doing that), and today I diluted some Lugols and just painted on (as well as over the FBD lumpy areas). I'm trying hopefully gentler solutions before resorting to the black salve that my husband used on a spot on his chest some months back. It worked beautifully, but I'm sort of afraid of how aggressive it is.

I don't know if there's any relation, but I had a pretty large birthmark middle of my back that was a little lumpy and occasionally itchy (though it sat right under my bra strap), and I had it removed about 8 or 9 years ago, no pathology, but given the spots are starting to look like it a bit and also itch.... makes me wonder if there's some strange connection.

What's the recommended dilution for the 5% Lugol's for something like this? 50/50? Too strong or not enough? Different dilution for moles & skin stuff vs. cystic areas where the lesions are deeper? Is is more effective mixed with oil or in a salve or cream, and should I soak a cotton ball with it and tape it down while wet, leaving on for awhile or overnight, or just dab it on and let it dry?

I'll start a new thread for the *ahem* intravaginal application....

Any suggestions would be much appreciated!