I'm assuming that as it is your website, you can have access to the source code and modify it to your own will. There are some solution offered in the link you posted.
The first one is using a javascript library like three.js to load your .obj models in a webpage. Cons: you need to do a bit a programming but that's quite easy to load an obj model in a webpage. Example with source code here: Three.js load obj example
The second one is using a webservice which will host you obj models, it will provide you a way to show your creation directly on their website or embed a model reader directly on your website. Cons: you can be limited in terms of model size, this may not be free, read terms and conditions. Example: Sketchfab
In both case, visitors don't need to install any browser plugin.
If you can't have access to the source code of your website, we will need more informations concerning your host, framework etc...