This is a reasonable question but the answer is not a simple Yes or NO. Here is a video from the Tire Information Association that covers the use of simple "plug" type repair.
This video shows an example of "hidden damage" and here is what that "saw tooth" can turn into. 
My post in 2017 has pictures of three examples of tires with internal damage that were improperly "plugged".
Obviously if just doing an external plug is improper then squirting "oatmeal" into a tire in the hopes it will block the air leak is not a good option.
It may look like this.