Hi! Well, a stray Saint is no different than any other stray in that you do not know its background, if he's sick, has any type of parasites, etc. So, there is your first caution, handle him as any other stray.
Yes, they're bigger and more powerful, however they are more likely to be gentle by nature than many smaller breeds. I'd be far less leery of a stray Saint than say, for example a stray Chihuahua. Do you know what I mean?
I grew up with Saints, fostered one named Suzie who was very very very malnourished and over-bred, and am getting ready to adopt a 3 year old boy named Dewey. I've never experienced an agressive one, although I have known some males to be non-tolerant of other males. (That's the exception, though-as far as I can tell)
As far as luring him in, yeah...FOOD. And just slow, cautious movements and soft talking. That should do it. I'd say if your home is open to foster, then do it! What a great thing! Be sure to have him checked immediately for parasites and stuff, so that he doesn't spread anything to your other dogs. I'd keep him separated if at all possible until you've had him to the vet.
Other than that, just general foster information. Well, lots of love, food, vet care, etc. If you're just fostering independently, then you kind of make the judgement calls as far as how you want to advertise him, how long you want to keep him before you do, etc. If you get hooked up with a Saint rescue or something, they'll sort of have their own rules as far as potential adopters, which vet he should go to, etc.
I've fostered independently a zillion times. Its always been a rewarding and challenging experience. This is a great place to come for ideas, help, support, whatever! We're really a bunch of super knowledgeable and loving people 'round these parts, and you came to the right place
Oh, and we love pictures, so get us some of that Saint boy as soon as you get him! And we'd LOVE to see pics of your Siberians!
Welcome!
Oh, and BTW, I'm Nicole. I'm mama to Cabeza, a Newf/Chow mix, and soon to be Dewey, a 3 year old Saint boy, who currently lives with another BPO member in West Virginia.