Replying to Cleaning skis?

Ive been skiing this rail in my yard since my home mt. is closed but its tearing up my skis. i figured my ski season was over soo i didnt care but im going to NY for the day tue. Also, now theres mud on them. I tryed to use a wet wash cloth to clean them but it still wont come off....what should i clean it with???And also theres this white stuff that i usually can scrape off with this thing on my ski wax container but i dont have it anymore... what could i use to get that off also...??