One of my nicest finds

[mikepietrello]

Heres a better look at the flat part

 

[mikepietrello]

THe Bottom

 

[bottlenutboy]

maybe the flat side was for a label rather than for laying on its side?

 

[mikepietrello]

Aha, I stand corrected
I love you guys!!!!

 

[beendiggin]

I would try some Cascade or other granulated dishwasher soap, a little water to make it slushy and an old toothbrush to get inside those corners....providing you can get the toothbrush in it. Normally I use this method and use BBs to shake around inside,but I don't think the BBs would work well with all those inside corners. Sometimes ripping up those green scrubber cloths and pushing them around with a small tool works well. Cool bottle, maybe it's a salt or peper shaker. By the way, does it have a ground top? Just curious.

 

[mikepietrello]

No I don't have the top . I was thinking salt or pepper shaker myself but I think Spencer was right. The flat side was probably for a label. I would think a salt or pepper shaker of the period would just be generic with no label, and this bottle is 6 inches tall.
Mike