Perjeta itchies again

Hi all, I am on the perjeta / Herceptin ride (4th year) and I've found the side effect referred to as the perjeta itch most trying. the worst thing about it is because my nails are very soft and thin when I do itch at night when sleeping I've track marks where I've scratched myself silly. So to the point of this post-- I was watching a gardening show a few months back on the ABC. and a fellow was spruking a home made recipe for relief from insect bites and itchy rashes. So what do I have to loose. Thought I would try first before putting it out there. Recipe for relief In a medium size glass jar fill to about a third with Epson salts and pour in Metho to fill jar mix together and liquid becomes cloudy then put in fridge. Giving a good stir when itchiest happen use a small brush and paint on area. I've had a jar in the fridge for over two months its wonderfully cold and seems to work well I've had to resist scratching for a few mins. Hope this helps some of you. lv to all