Thank you for contacting us! I am sorry to hear about this power issue, I am happy to help.
I have tested one of the USB 2.0 Sharing Switches, the switch is powered by the active host port (A or B) and has a power consumption of about 7mA with no devices attached.
This draw should only be significant if the Raspberry Pi has an insufficient power source and is on the verge of being taxed as-is.
When using the Raspberry Pis with a sharing switch, I recommend adding a powered USB hub after the sharing switch to reduce the load on the Raspberry Pi when powering attached equipment.
Here is an example setup
Raspberry Pi-1 --> USB Sharing Switch \
> Powered USB Hub --> Devices
Raspberry Pi-2 --> USB Sharing Switch /
Please let me know if you have any additional questions!