You are correct that products with an active ingredient of triclopyr can be used to control wild violets but products containing quinclorac,, fluroxpyr will also be effective. Some products are actually call ed Triclopyr.
You will find products with these active ingredients at any local nursery or big box store typically listed as broad-leaf weed herbicides or wild violet herbicide.  Any brand name product containing the above ingredients will be effective so there is no specific name brand we would recommend.  Just make sure to follow the application directions as listed on the label.

Below are links to a couple MSU articles which will provide you with more info about fall herbicide application.  Violets are very challenging to eradicate so more than one application over several seasons may be needed.   You can also apply an herbicide in the spring but since plants are storing energy in their roots as they head into winter, fall is an ideal time for an herbicide application.

 If applying an herbicide in the spring, pay special attention to the fact that once the violets have flowered, new seeds will be released for the growing  season.  To break this cycle of re-seeding, apply the herbicide before flowering. 

http://msue.anr.msu.edu/news/tough_to_control_broadleaf_weeds_flowering

http://msue.anr.msu.edu/news/fall_weed_control_in_turfgrass

Hope that helps!