I am sure most of you guys know this but just in case I thought I would share what I have found to be the best method of cleaning my Nubuck straps...
I was advised sometime ago to use a fine grit paper but I found this was a pretty destructive method..... so I managed to find a commonly available nubuck cleaning eraser bar....I know in the US it can be sourced from any shoe shop but in UK it is slightly harder though I found a source on eBay...
The great thing about this bar is if you have say a surface stain like toothpaste then lighly rubbing with the bar will remove it without disturbing the grain of the nubuck, if the stain is more saturated, such as grease etc then rubbing harder across the whole strap will still maintain its look and remove the stain....
I think its a great way of maintaining your nubuck especially the croc nubuck where grain is everything...
Here is a pic of the kit I mean
Here is some pics of a recent fix, the first shows a grease stain by the lugs the second shows it once removed...