Periodically, through them in the wash for an overnite soak, using a good quality degreaser. After a good 8 hours, run the wash cycle. Then, wash them again using detergent and bleach.
On new coats, iron them after a wash, using spray starch. I have found that this retards the absorption of grease vapor. This is what makes the coats look grey and dingy.
Now, would you like to know the best way to clean the mirror over the bar? LOL
my amazing chefly powers retard stains and grease!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! but when that doesn't work, for really tough stains(you gotta do this the same day of the stain) and this even works on carbon from the bottom of the pots. make a paste of powdered detergent and bleach, then scrub into the stain with a brush,,, let it rest for about an hour then wash as usual,,, if that doesn't do it you just gained some good rags for washing the car and changing oil.
I use cascade, i add the powdered cascade to my wash with the regular detergent or bleach, and it takes out the food stains very well... hey it takes grease off of out dishes and pots whynot out clothes.
what i do is SHout! or any other good stain remover for clothes. i spray it on my uniform and let it sit ivernight or up to 3 days. but you gotta do it after your shift because if you wait another time the stain is in for good. i said up to 3 days cuz that way you can wait to wash more than one uniform, save on electricity! after that you just wash at regular warm cycle with regular detergent and it comes usually really mighty clean. since you dont use bleach the uniforms dont turn yellow. and i do use it heavely. almost a bottle a week. but it's goooood!
Bleach is not always the key, because if you are like me, and have Black or Dark Piping or lettering on teh jacket, it will change the color of it to like a dingy brown. I spray Tilex directly onto the stain, it comes right off.
Pre-wash stain treatment applied immediately when arriving home and then OxyClean added to the water when washing, Dry Cleaning and Laundry services have all benn used with varying degrees of success by myself. I later found it better to have two or three jackets in the office. One work, one work spare and a FOH schmoozing coat. This one was usually my best dress coat. I gave up on the harder working Sous Chef long ago Although there were one or two out there.