Good morning,

We have had our besenji now for about 6 months. He is a rescue that had some traumatic experiences and we had to do alot of work to get him adjusted with his new home. We have been to obedience training and he did great if you show him treats then he will do anything we ask. But without them good luck. Lately he does not want to listen at all and its like he completely forgot everything we tough him. For example if we dont pay attention to him for 5 min he goes and digs in the couch or chews on storage containers and often when we put him in his cage he will have a tantrum and wreck his bed and blankets. Anyone else with this issue? Anyone have any tips?

For starters, treats should be good quality and low calorie.
I always used special treats for different activities. For example, treats I used in obedience class had to be high quality to counteract class distractions (often I took cheese) but treats for home practice could be simple Zuke minis. Treats that I use for recall rewards I never give any other time.
Never use the crate as "punishment" - even if it is for "time out" give a treat - always make it a happy place. My dogs get a biscuit for crate time and never get that biscuit for any thing else.
Yes it means I have bags of different treats around (yee gads).
Additionally treats have to be gradually removed with lots of praise substituted. If you do clicker training, this will go a lot easier.
Most importantly, the sudden change in behavior could signal a medical issue. Perhaps a tooth has gone bad. Check with your vet.

How old is he? What do you know about his background? Using food rewards in training is usually an effective way to teach new behaviour but it is important to move to a variable schedule of rewards once the dog understands what you have taught him and has it on cue, i.e. will do it when you ask for it. If he does not know when he will be rewarded but that there is a chance it will be this time, he is more likely to comply with your request.

Having treats visible is a mistake, IMO. If you are working on something in your house vs when you are out walking, then don't even have the reward with you. When you get the correct response go and get whatever you are rewarding with. That way the dog doesn't refuse to work when he knows you don't have the goodies on you. (make sure you "mark" the correct behaviour either with a clicker or with a marker word when you get it, so he knows what he did to gain the reward).

In what context does he wreck his bed and blankets? When you routinely crate, or when you crate after he has been acting out, digging the couch, whatever?

Your dog is telling you he is bored. Honestly the more tired you get him, the better he'll behave.

Just a suggestion: When you see him "misbehaving" by chewing on 'less than ideal' items, offer him one of his toys and use the word "trade". In other words, 'chew on this instead', and when he accepts the toy - praise him. And when you see him get the toy on his own, praise him again. It could help him understand that certain toys are just for those times when you want to "rip someone's head off*".

(*not meant literally, only in doggy world play)