Seller Beware ! I went through this selling a house last year.
Was told buyer had 100% mortgage and was not in a position to pay 10% deposit. But they would close within a week or two with full amount issued so I said ok fine and signed contracts.
Buyer was refused life assurance on medical grounds, cheque could not be issued, sale fell through. This took about 2-3 months to sort out before I could actually put house up for sale again. At which stage we were into the late 06 slump so lost a lot of time and money as a result. If I had received deposit, this at least would have provided some compensation.
How buyer arranges their financing is up to them, but you should insist on the 10% deposit to ensure you are covered if any problems.
Banks issuing 100% mortgages, normally provide a short term loan to cover the 10% deposit. Its up to buyer to ensure this is organised.
If it was me now, I would insist on the 10% deposit being paid.