Kegs as cloches?

Good evening all,

I came by a few of these (see pic) today, they are use once plastic beer kegs. The one on the left is a 30L the other a 20L. apparently gardeners use them for cloches? We have about 30 with a promise of a lot more.
Before we get to excited I thought I would run it pass the members for their views. Looking forward to them.
Echium

We agree, and was thinking of 3 or 4 3mm elongated slots at the dome end and may be a couple 2" up from the base? 3mm is the width of a circular saw blade and with a jig it would easy to machine them.
As an experiment in early March we will set some your plants under a line of these with a supported thin timber frame around to protect them from wind. I will report back on how things do. My thoughts at the moment are they may make it easy to access individual plants without uncovering them all?