Can the RNeasy kits be used to extract RNA from saliva collected using the Oragene collection kit?

There is a protocol available at the manufacturers (DNA Genotek) homepage: http://www.dnagenotek.com/US/pdf/PD-PR-021.pdf

There is also a White Paper available demonstrating the performance: http://www.dnagenotek.com/US/pdf/PD-WP-008.pdf