Hi Dave,
Like you I have a stricture, that closes up a week after a session of Chemo,
{  I am  having early Chemo for recurrent PC with three Mets ,}
Glad to see you are still on HT with no spread. 
 
I use SpeediCath® Compact Male  which are easy to carry about ,  I always use some pain killing gel as well .
Hope you are well Dave