There is no reason to dissolve a Klonopin under your tongue.
It's a popular misconception that all pills can be ingested anyway you want them to be. Pills are designed to be orally active ONLY. The pill is not designed to be absorbed by the buccal tissue under your tongue and therefore, none of the Clonazepam is absorbed into your body when the pill is dissolved under your tongue. If you get any effects from it; it's entirely placebo.
Also, in the case of Clonazepam specifically - it's bioavailability is exactly the same, no matter what route you take it. You will not increase it's effects by snorting and will only decrease it's effects by dissolving it under your tongue.
Where have you heard this? Some patients are prescribed clonazepam to be taken sublingually, and the pills have a decent taste to them possibly for that reason.
This means the pills are supposed to be dissolved under the tongue and therefore are designed to be absorbed by the buccal tissue. If the pill isn't specifically designed for buccal absorption - dissolving it under the tongue will do nothing. The OP said that the pill was for oral administration. Since the Clonazepam formulation in the oral form isn't formulated to be absorbed by buccal tissue - it will not be absorbed.
Also the bioavailability for Clonazepam specifically, is the same for orally administration, and insufflation. Snorting Clonazepam won't give you a better "peek" and is, therefore, unnecessary. Also, if taken orally, the absorption of the drug is slower, but will therefore, last much longer.