Absolutely… many people use BigFix like this to manage the laptops that are at home, in a hotel, at a coffee shop, etc. Here is the basic idea:
Put a relay in your DMZ.
Establish a public IP address or DNS name that will allow computers to address the DMZ Relay.
Open the BES port in the firewall so that the computers from the outside world can reach the relay and the relay can reach the BES Server (or a top level relay).
Use the Task on the BES Support “BES Relay Setting: Name Override” and use the IP address/DNS name that is publicly accessible.
With all this in place, the BES Clients will be able to find the BES Relay (using automatic selection or if you manually point them to the relay). The cool thing is that as long as the computer has an Internet connection, you can manage it as if it was in another one of your offices. This greatly helps the huge security issues surrounding mobile computers (which are the most exposed and hardest to update).
By doing this, you are opening a hole in your firewall that could lead to specific attacks on your BigFix system. This is an inherent risk when you make public Internet services.