Find a way to delete Trash in my gmail order immediately.

I have a Gmail folder that gets a lot of spam. much of the spam is what I would consider very bad spam. Since my kids use my Gmail account, I want to find a way to automatically keep the spam and trash folders clean of deleted email. I know I can delete the email anytime I want, but don't have time to do this. I know I can create filters which send an email to the trash folder, but what I am trying to do is create a way to automatically keep the spam and trash folder clean all the time. I don't want any email to sit in those folders. I am trying to find someone that can help me solve this problem. If you can solve this problem, please explain and give me a price to solve it.