I have an absolute minimum of 1 hour for even the lightest of road walks but if we are heading into the fields (which is more usual) I leave it for 1.5 hours minimum but prefer 2 hours.
Bloat is a concern but it's also for other reasons: I don't like them swimming on a full stomach (several of my regular walks include a slosh about!), and it works with their guts better - they are ready for a pooh! Two of my dogs will pooh at least twice on walk, and don't go in the garden, so it makes sense for me to give them the right sort of walk at the right time :)
I have a (terrible) technique for the steam train effect on the way home. One of mine has to be washed after every walk (allergies), the other two also get filthy so all three get a cold hose and a Hibiscrub wash when we get back. As we get closer to home they resemble small boys being taken to the dentist, and then have a very polite exchange at the gate...
"After you", "No, after you", "No I insist, after you" "No really it's OK, I'll wait" ... :)
aw,bless!Stiil,dogs a babe,at least they come back clean this frosty weather,aw,i can just picture them!