Mustard and/or Mayo in tubes?

[Mohamed Ellozy]

Many thanks to all of you for the useful suggestions. I was unaware of the existence of refillable tubes. However, I do not need them, as Carole has made an absolutely brilliant suggestion:

The tubes are a nice idea but if it is for just a day hike sandwich you can put the mayo or mustard on, just don't put it on the bread, instead put it in between the layers of what ever meat/cheese/veg combo you are using.

Thinking outside the box at its finest!