The first 6 weeks of the year is DEAD, at least in our salon.  We offer an hourly guarantee as well and I TOTALLY understand where the owners are coming from.  On occasion over the last few weeks, when it was a non-productive day and my wife is in the salon, she would offer to let someone go home if they wanted to.  She never forced anyone to leave.  They always take us up on it because they are bored stiff, you can only clean so much, re-fold the towels so many times, etc.

Simply offer to clean, dust, restock, organize, data entry, whatever you can think of, when you see its slow.  Its harder to send someone home if they are busy doing something productive, instead of slouched over in their chair reading a book or watching Judge Judy on the TV.

As long as they are keeping someone in the shop to cover walk ins, they'd be silly not to send home anyone 'extra'. My dad is a store manager for Albertsons, and THEY do this. It's called labor control, yes, businesses do have practices in place to keep costs down during slow times, and reduction of labor is one of the main ones!!

I'd say your best bet to NOT have this happen is to NOT appear to be 'extra'. Always be doing something! And the best thing to be doing, is hair. It may be 'mostly a walk in salon' but that doesn't mean you can't /shouldn't be out trying to get yourself new clients. If you're cutting hair, they won't send you home. Most places , even those that don't allow appointments, will allow people to request a specific stylist. Make sure you have people coming in and asking for you, and when it's time to cut labor, you won't be the one they think of.