I have been under H1B visa since 2011. I would like to invite my parents to US under visitor visa. I have been able to gather all the information regarding the procedure and documents required, but would like to get personal opinion from those who have successfully invited their parents. I have few questions:

In order to enhance social and economic ties to Nepal, would it be beneficial for my parents to sponsor themselves for the travel, or that isn’t an option since I’m inviting?

This is the third occasion they will be applying. First time was for my graduation, second time was under my H1B. They were denied both the occasions. Should I have only my mom apply this time, so that she can show social tie to Nepal? My mom doesn't have any property/bank account under her name. Will this lessen her economic ties to Nepal.

Thanks in advance.