I have read a few of your post

I have read a few of your posts so I feel you are the best person to help with the following:

I am looking to get a mortgage but have had negative credit issues in the past. The only two debts I currently have are an auto loan and a student loan, both being in good standing. My credit scores are 575, 643 and 655. The 575 is being disputed due to a collection that was paid 2 years ago that is still showing as being owed. The mortgage company I am working with has suggested I open a few credit cards with a few thousand dollars each and charge half and pay a few hundred dollars a month to show established credit. They said this would increase my scores and give me a better interest rate in 3-4 months. Is this accurate? I currently make $170k and am looking at a $300,000 mortgage. I am also a first time homebuyer. Let me know what you think! Thanks