Visa application at HK airport for a 2 day trip into shenzen

Hi We need to get an urgent permit for a client to inspect product being shipped next week so need a rush one to be processed at HK airport. they only have 3 days before they need to be in Shenzen.

they have a lebanese passport, will this take the normal time of within a few hours to get at HK airport, the same as a British passport??

Mark