From what I've read, it's 1-2 times per day. I plan on using the gel with her tooth brush for the first 2-3 months until the plaque is cleared up. Then, I'll use the spray 1 time a day for maintenance and brush her teeth ~3 times a week. I ordered mine from eBay because the shipping was only $4 for USPS Priority Mail.
http://cgi.ebay.com/ws/eBayISAPI.dll...1336&rd=1&rd=1