I don't allow blankets or lovies at all until they are over the age of two and only in their beds at naptime. I have a separate nursery for the under two crowd and don't allow blankets in that room at all. We use blanket sleepers (sacks) or footed pajamas over their clothes at nap for warmth.

I have found that attachment items are escalators and draw the kids away from what I want them to do which is "go play toys". Anything that interferes with them playing toys independently will not work here. I also don't allow any child to own anything that is available. I own everything so we don't have any "mines" or hoarding behaviors.

I would just cut him off of it completely. Put it up right when he arrives and give it back as he's getting ready to leave. You can see how unhappy he is about it. Release him from the fixation by just not making it available. This will de-esclate him at your house and make him love it even more at home which will buy much peace and quiet for mom at home.

I have kids here who are blankie and paci addicts and they have never had them in my home but carry them and suck them from the time they leave till they get back. They do fine with different rules for different houses. We don't have to copy what parents do at home. We are raising human babies and they are designed to be very adaptable.