I just cleaned my coffee machine (Nespresso Pixie), it wasn't as dirty as I thought it would have been after ~18 months use
I used 3 tablespoons of Dezcal for the 0.7 litre water tank of the Pixie
In case you want to clean your machine out, I bought my dezcal Prubuy - tip: buying the powder in the container is MUCH cheaper than buying individual sachets, especially if you compare to the Nespresso branded sachets.
Dezcal is an industry stalwart, so you're safe with it and of course can be used to de-calcify any coffee machine
http://prubuy.hk/
Ordered 30 October, Arrived 12 November
Urnex Dezcal Activated Scale Remover, 35.27-Ounces
$58.86 SGD $353.272 HKD