Made me chcuckle... 110% on every thing 3.5 years old and wount stay to ground more that 5 minutes! Dount want to sound nasty but i dount think you will have much luck with that dog.
biggest load of bollocks iv hurd in a long time, weve had russell dogs from 4 years old and shit scared of going too ground after, after theyv seen one of the other dogs go too ground a couple of times they are on it like gin nd tonic so what you have just said my freid is utter bullshit i think the lad is right in what he is saying someone with an experianced dog will sort his dog out, maybe hes sevente