I personaly would not recommend the purge valve. Its just one more thing that over time can fail.
As to getting water inside the mask I think just being underwater in itself will to some extent put some water in the mask and I know I clear mine quiet regularly.
If in doubt though as others said just experiment at the LDS
As to getting water inside the mask I think just being underwater in itself will to some extent put some water in the mask and I know I clear mine quiet regularly.
If in doubt though as others said just experiment at the LDS