954 I have never been a big fan of the wireless fences for safety reasons, especially because it doesn’t keep anything from coming into the yard. But, I do see how they have their uses if dogs are not left unsupervised out on them.
That being said I definitely would not use one on a pup unless they were over 6 months of age at the youngest and have had at least a month of boundry training by walking the dog around the property border on a leash and leading back to the center when they hear the tone from the collar (with the prongs taped up with electric tape or rubber tips).
You want to use a lot of caution using invisible fence collars on a pup because they are new to the world and are sometimes still fearful and discovering what is considered normal out in the yard. There is a potential risk of causing various types of environmental fears if they get corrections that they do not quite understand – especially since invisible fence collars generally use higher levels (avoidance levels) than you would use with other types of training (threshold levels) with remote devices.
I would recommend breaking the training into 3 phases similar to how we would do with obedience.
Phase 1 – safe walks around boundry and reward for staying in. Gentle guiding back when you here a tone from taped collar.
Phase 2 – similar but use a leash correction just motivational enough where the pup seems to have a desire to avoid it when he hears the tone.
Phase 3 – Expose the dog to the untaped prongs, but be ready to guide into the yard with a long leash if the dog gets confused/panicked
Maintenance – Do proofing, etc.
I would stay at phase 1 until 6 months of age and at least a month practice to play it safe.
Also, use the flags for your own reference only as to where the boundry line is – teach the dog the boundry , and not to avoid flags. The old holding the flag and saying “no, no, no” technique has proven to confuse a lot of dogs for many years now but some trainers of the system still do it for some reason.
Good luck with your Corso!