For frost, I found the single best investment I have ever made was to go to B&Q, spend £10 on a small garden sprayer, then go to the airport and spend £15 with the tower on some deice fluid mix.
5 minutes with the sprayer and a towel (for slightly thicker bits)- all frost gone (makes winter flying so much nicer). Worked for me all last winter and I had enough left over to use it as an instant windshield de-ice this year (before I buy a fresh batch).