Frequency of washing ski jacket and pants for non-frequent skier?

Hi! I'm a casual skier. I actually live in a tropical country, and only make 1 ski trip for about 4-5 days of skiing per year. Some years maybe 2 trips. How often should I be washing and reproofing my ski wears?

I bought my current ski wear last year then wore it for 4 days. It didn't get very dirty so I didn't even bother washing but this year I'm thinking I should wash it... I bought Nixtek Tech Wash and Tx Direct Wash-in for reproofing. I'm thinking I'll just wash with tech wash this year and reproof it some other year? wdyt?

Also, my ski jackets are lined. I read that the Tx Direct Wash-in may not be the best for this. is this true? the direction doesn't mention anything about it.

Thanks in advance!