Clean stitching on leather seats

[RV08]

Is there a product that will clean the stitching on leather seats to turn the stitching white again?

[shadwell]

Some diluted APC and a fine brush then dryed with a coton towel has lifted dirt from mine previously with not adverse effects...

IF it is stubborn try wetting it more scribbing with the brush and then using a umn (narowest head attachment) to extract the cleaning fluid.. (bagless or wet and dry.. as really there is bugger all fluid volume there..) then rub with the clean towell... and allow the car to air afterwards

I haven't had anything that reqwuired more than that, and would be hesitant to go more harsh on the chenical front...