Whats your views on using a soil that got left out in a bucket in the rain, has that unpleasant smell about it. Only left for 2 days like this. Will it be ok to use if i get sufficiant air to it? Or should i start again?
Totally safe once you aerate it some more. Don't dump it or throw it away.
Dump the soil out and mix it up, mixing and turning multiple times a day. Once the bad smell is replaced with the good smell, you'll be okay to use it. However, you will have to re-amend it a little bit as you're mixing it up.
Reason being is because that smell you are smelling is ammonia; a form of nitrogen gas. So, you're quite literally smelling your Nitrogen "evaporating" and will need to either mix more amendments in, or simply top dress more frequently to compensate for the loss.
Easily salvaged though. Just sprinkle in 1/4-1/2 of the amendments you used when you initially made the soil. Then dump it, and keep is evenly moist and aerated. Mix it daily, preferably 2-3 times a day. The more you mix, the sooner it'll be good again.
I only used trash cans/containers for soil twice, almost always go anaerobic and need to be dumped on a tarp and turned multiple times a day. So, I just stopped using cans to store the soil and just leave it out in the open.
With enough turning and mixing, your soil should be back to normal in under a week. In fact, since you only have a small bucket, it'll likely only take a day or two.
Hope that helps.