Looking on the internet deeply has found these results:

thanks for helping is the most popular phrase on the web.

thanks to helping 113,600,000 results on the web	thanks for helping 129,900,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:

thanks to helping

113,600,000 results on the web

thanks for helping

129,900,000 results on the web

More popular!