Instead of a zippo, I used a candle. I removed the strap from my bag and held it over the flame, moving it around to get a good coverage. I had to keep it really close to the flame otherwise no soot would form on the strap. I made sure the strap was, as much as possible, covered evenly with soot.
The strap was basically black at this point because the soot was all over the strap. I then proceeded to apply Lexol to "seal" the soot in... at first I accidentally wiped off the soot and had to re-"soot" it. Then I found that dabbing in the Lexol and letting it dry was better.
I re-applied around 3 more coats of Lexol - with around 5 - 10 minutes rest per coat. When I felt that the strap wasn't tacky anymore from the Lexol I had applied, I wiped it down several times to test if any of the soot would come off. Surprisingly, none came off and the darker shade stayed on.
Here's a pic... Unfortunately, I never got to take a "before" picture.
As you can see (if you're familiar with Todd's strap, which I'm sure most of you are) it has darkened significantly from the original color.
