Jamie,
Unless your confident in the person selling your services and portraying your business as you would want then i would say no, unless you can get a salesman to work on a percentage basis of course, bearing in mind he most know all the ansers to the questions he will be asked , be able to quote for a job etc etc.
The best way ,get out and do it yourself

I went out with my brother the other week door knocking pushing my pressure cleaning side of the business on one of my quiter days, he could not push his self to knock so just fropped flyers, i spent 2 hrs and booked 2 jobs, £180 leading to another £150 for the rear of house when she saw differnce and a £260 job further down the road.
Geoff