My roommate has a one-year old Pekingese who is usually a very sweet dog, but she gets really agitated when she has something in her mouth and someone tries to take it away. For example, she loves tissues and underwear (usually of the used variety) and will knock over garbage cans/laundry baskets to get to the stuff. Then she takes it and hides under a bed where no one can get to her. If you try to take the item away, she bites pretty viciously. Now, she's a small dog so her worst bites bruise a little bit and might break the skin, leaving a tiny cut, but in my opinion, the size of the bite is irrelevant; the dog should not be biting. I also realize that one solution is to keep garbage cans up high or behind closed doors, but this to me also seems to be avoiding the issue, which is that even if she does get into that stuff, she should not be biting when someone tries to take it away.
I have had a few dogs, but they never really misbehaved, even as puppies. What I've been doing when this problem occurs is grabbing her and putting her on her back until she breaks eye contact, then taking the item. Sometimes she lets it go, sometimes she bites when my hand approaches her mouth. She never drops the item by herself, even if I wait for 5 minutes. I try to stay calm and keep my voice level, while strongly saying "no" and "no biting." I also put her into the kitchen (which has a little fence-like thing so she can't get out) for at least 10-30 minutes each time she bites. I never hit her (one of our friends smacks her in the face when she bites, but I don't really think that's a solution either). Unfortunately, this does not seem to be doing the trick. She bites me at least once a day. She does not often play bite; it's almost always in anger. I also try to avoid playing games with her where she wins (such as tug of war) -- at most I'll play fetch or just run around with her.
She doesn't only bite me. My roommate has said that her family refuses to even attempt discipline with this dog, and all of our friends are scared to dog-sit. I'm the only one who continues to challenge her. I don't want to stop that, because I feel like then the dog will continue to be disobedient and troublesome with me, even if she obeys my roommate. The fact is that my roommate is not always home and sometimes I will have to pull the dog out from under the couch or my bed, and take stuff away from her. I also think that once I have gone to take something away from the dog, I cannot back down or she will think she's the boss and will stop respecting me (not that she respects me now...).
My roommate says that she will look for an obedience trainer but in the meantime, I would like to avoid the daily biting. Any tips on how to avoid getting bitten/stop the dog from biting?
tl;dr: One-year old Pekingese who belongs to my roommate bites me when I try to take stuff away from her. How do I make her stop biting, and how do I avoid the bites if I can't make her stop but still need to get ahold of her?