I have worked in at least a couple of dozen different psych units all over the country during the past 30 years. Every place has a different policy regarding safety checks and searches.
i can assure you that you are on the extreme end of the spectrum. Q shift checks are way beyond the norm. Having patients turn out their pockets after being off the unit is way beyond the norm. You are correct that there needs to be a balance between safety, privacy, and what is reasonably possible with the resources you have.
I would suggest that you research psych facilities in your area, or similar facilities anywhere, and find out what the norm is.
Don't expect your nurse manager to be swayed by the evidence, however.
One thing I have learned is that, with a few notable exceptions, once a manager believes that things MUST be done a certain way, no amount of evidence to the contrary will change their mind. Actually, this also applies to staff who have only worked at one facility.
Here is a reasonable plan based on the best I have seen... usually worked out by experienced staff during many years of practice:
1)Take all pt. belongings BEFORE they come on the unit. Have the belongings searched by staff and separated into four piles: Stuff they can have back immediately, stuff that needs to be locked up and used under supervision, stuff that will be locked up and returned upon discharge, and illegal stuff that will either be destroyed or turned over to authorities.
If your pts all come through ER or from other hospitals, it's best if they're changed into hospital gowns before they come on the unit so their clothes can be searched.
2)Do check everything brought in by family/friends. Allow visiting only in community areas that are monitored by staff.
3)Do check pts on return from pass. (Few places actually allow passes any more.)
4)Have Day and Eve charge nurse do room to room rounds at change of shift, but this just needs to be a quick look at each room.
5)If there is reason to believe that there is dangerous contraband on the unit, call a community meeting and have two staff search room by room, with the pt present if they so desire. This should happen rarely.
6) Finally, teach all staff to be constantly observant. When you need to go in a pts room, look around. If you see something that shouldn't be there, calmly let the pt know that you need to take it.
Most of the time, pts will act as they perceive you expect them to. If the environment is one of suspicion and total control by staff, then pts will not feel obligated to show any responsibility for themselves or the community.
Enough. I hope this might help generate some thought and discussion at least. I have helped start two different units from Day I and also helped two units in the transition from open, totally voluntary to closed invol., so I've thought about and worked on these issues a lot!