Phone went through the wash

I had an iPhone 7 Plus go through the washing machine  and it still works!  For some reason they wouldn’t just replace the battery for me , I think it’s because the battery has swollen and is pushing apart the side of the phone a bit.  They told me to get a new phone because it would be $349 to repair. I did let it dry it out for two days in a bag of rice. Since I owe $292 on it yet,  I am going to use it. Has anyone else done this? Is it safe or might it explode?