The best mouthwash we found was baking soda and salt.Recommended to me by a lot of people on this site,it consists of one teaspoon of baking soda,one teaspoon of salt ,and water .
Rob also used biotene mouth wash and gel .Biotene does a full range of mouth care products and you can source them all on the internet and at major chemist shops.

Liz in the UK

Husband Robin aged 44 years Dx 8th Dec 2006 poorly differentiated SCC tongue with met to neck T1N2cM0 Surgery and Radiation.Finished TX April 2007
Recurrence June/07 died July 29th/07.

Never take your eye off the ball, it may just smack you in the mouth.