Help with scrapebox returning good blogs to post comments on

I have been using scrapebox to try and get some high PR results to post comments on but all of the results I am getting back are junk. I am using keywords that match my blog to try and keep it related.

Should I try using different keywords?
Is there a way to filter the blogs to make sure they accept new comments? I am using the blog analyzer plugin but that is not helping.

how many times do you scrape for keywords? i use 2 times maximum cause it starts to scrape weird keywords after the 3rd time

I am only doing it once then I change keywords.