Thanks for the feedback everyone. I use Orange Seal. I have had a couple of punctures and the only way I knew about them was b/c when I arrived home my bike was covered in sealant. Had I not seen the sealant on the bike, I'd never have known about the puncture.
Then I had a puncture a week or so ago. The sealant sprayed everywhere. Definitely did no plug the hole while I was riding. I stopped with the sealant/hole at the top but no luck. The sealant would not do the trick. So I used a Dynaplug and that did the trick. Pumped up the tyre and was able to finish my ride. I rode on the tyre for several long rides after that too. The plugs held. But as the tyre had 9,000+kms on it I decided to play it safe and I replaced the tyre. However when I took the tyre off and inspected it, there was still a good amount of tread left and the sealant had sealed over the Dynaplug. I probably could have continued to ride the tyre for another 1,000km.