Len,
I've been reading another thread about how we all clean carpets and it seems that not all cleaners use a dry vacuum cleaner so I would have to say that. Buy a Sebo BS, no carpet cleaners van is complete without one. Everybody so far has mentioned extras to make the job better or easier but suprisingly nobody has yet thought of personal protection, if I had to choose one item it would be protective gloves, latex, vinyl etc.
I've also avoided overshoes until recent years because I didn't want to look a prat, but to my suprise they go down very well with customers, in fact most people expect us to wear them. As a PR tool they are excellent value for money.
Nobby
Nobby