Love the thread drift into MAC land.
Yep, and that means the router will remove the frame from the packet and replace it with its own, meaning the packet now has the routers MAC address on the internet. And as that packet continues getting re-routed on it's journey to its destination it keeps on getting a new MAC address.
From memory, to change a MAC address on a Windoze PC just requires you to make a small change to the network policy and then you can go to network properties and there is a new tab available that allows you to enter any MAC address you like. This is a commonly used trick to re-activate licenses restricted to MAC address (rare now) when the network card dies and is replaced and the reseller that sold the original license has disappeared.
Now back to the OP's question.
Don't fiddle with cache, cookies etc. Just run your browser in anonymous/private mode.
On a side note, I found I could continually vote for a pop star friend who was on tour in the US and engaged in marketting obligations by simply clearing the cookies and voting again. I got her to second place
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