John Kelly is the man for this...................with respect there comes a point where you will need to hot water extract the badly soiled areas, then go with the Dynamall. Only you know how bad it is but on any commercial job do not attempt anything that you cannot deliver. They may want quick drying times in their dreams but above all else they want it clean as a given. Look at HWE if necessary and doing ity out of hours so it can dry.................then you need to decide if you can get a premium for this - that's for you to decide.
Everyday this forum slips further from God.
I reckon John Kelly is correct. If as Bernd says - the restaurant carpets aren't to bad - then you can achieve good results with bonnet together with encap. If you have black top usually coming out of the kitchen then HWE with a truckmount set at high heat is the only solution