Koshering a milk frother / immersion blender

Pesach
1

Hi,
I have a glass milk frother that I only use with milk but the part that froths is metal and plastic. Can I use it? Is there a way to kosher or no need?
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Also my immersion blender stick is metal but the top attached is plastic. I guess it’s the same issue. Is koshering possible?
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Thank you for all your help!

2

You can kasher it by frothing or heating water instead of milk. However it is not necessary to kasher it as per your description.