Steve,
I'll second Pauls' attitude to bleaching of fringes. Some will advise the use of APR or hydrogen peroxide but I feel that since oxidisation weakens the fringe, it should be use only as a last resort, and then only after advising the customer of the fibre damage.
For really dirty fringes:
1) Place suitable plastic below fringe and pre-spray as appropriate - generally B108 Fabric Restorer but specific soiling may indicate an alternative product.
2) Work in pre-spray. Either a tampico brush with firm presure from web outwards or express with roller.
3) Re-treat with pre-spray, place doubled terry towel above and below fringe and power blot, either with roller or heavy dabbing.
4) Extraction rinse with acidic agent such as B109. To avoid tangling, use tool upside-down (hose-up), drawing tips into tool first, then advance tool towards web. Place left hand, palm towards you near opening of tool and spray onto hand so that the rinse is drawn into tool, passing along the fringe-strings.
Whilst spraying, draw the tool towads the fringe tips. When you reach the tips stop spraying and advance the tool back toward the web. Repeat the former motion, without the spray, but this time with the left hand forming a partial restriction whilst you move back toward the tips.
5) If required the power blotting can be repeated with fresh toweling.
Sounds complicated but feels natural with a little practice.
There are variations on the above that I use but it would take a booklet to explain.
When discussing the clean with the clien, always make them aware that a dirty fringe always looks worse befor it looks better and that the final result will not be seen untill completely dry.
John.