When i was new with magento i was get lot of problem with this wysiwyg text parse. i try to do that manually with php code. But after move inside the magento core function i found that method how simply parse the variable for the wysiwyg text description or custom module text.
Magento has the simple
$_cmsHelper = Mage::helper('cms'); $_process = $_cmsHelper->getBlockTemplateProcessor(); echo $_process->filter($_product->getMyCustomAttribute()); //pass the variable which is use to display content of wysiwyg editor