A sacrifice

I've been getting these spam phone calls and Nerys at work told me she went to this phone shop where they blocked some dirty phone texts.

If Nerys hadn't sworn by the place I would have thought it was a scam.
"I can help but it will need a sacrifice of great value", the woman told me
"It will be expensive".
I paid and she pulled out this bottle of red liquid and started sprinkling it all over the case of the phone. I must have looked a bit pale because she said "Its not blood, it's magenta printer ink"