It doesn't seem so. This is a malapropism by your client. See below:
From Macquarie’s dictionary of Australian English - paywall, so no link.
/swɒp/ (say swop)
verb (swapped, swapping)
–verb (t) 1. to exchange, barter, or trade, as one thing for another.
–verb (i) 2. to make an exchange.
–noun 3. an exchange: *If you're really worried, bring along someone else's in a thermos and do a swap in the cubicle. –JOHN A SCOTT, 1988.
–phrase Colloquial 4. swap spit, (humorous) to tongue-kiss.
- swap the witch for the bitch, to give up one addiction for another which is even worse.
Also, swop. [Middle English swappe strike, strike hands (in bargaining)]
/swɒb/ (say swob)
noun 1. a large mop used on shipboard for cleaning decks, etc.
Medicine, Veterinary Science a piece of sponge, cloth, cottonwool, or the like, often mounted on a stick, for cleansing the mouth of a sick person, or for applying medicaments, taking specimens of discharges and secretions, etc.
the material collected with a swab.
a cleaner for the bore of a firearm.
Colloquial a contemptible or useless person.
–verb (t) (swabbed, swabbing)
6. to clean with or as with a swab.
to take up, or apply, as moisture, with or as with a swab.
to pass (a swab, etc.) over a surface.
to test (a racehorse) for possible drugging by taking a saliva sample with a swab.
Also, swob. [probably Middle Dutch swabbe mop]