He's got some secret method and exclusive group that you "need" access to to be successful.

Then you've opened Pandoras Box and you instantly have the guys in the HazMat suits with fans and plastic sheets all over.....and a bill for $5000 for something you could have done for $50.I used to do this kind of work on the weekends when the city inspectors weren't driving around :-) haha , one time the hazmat guy come down to check for asbestos checking ; it wasn't that bad it's actually 2k and insurance company for that in my case.( To be honest, the house with water damage is good to buy because it scares the potential buyer, but if it's located in good location we could sometimes purchase the house with 10-30% discount lol but nowadays even FTHB knows this secret too so they still overbid the house )but yeah, to the OP, if you want to be sure you have to cut the drywall, the more the better.

Not to give away your secrets but you can become the next influencer showing the ground up and the crew smiling, even the flub the dubs.

Be wary of any of the courses that profess to teach you the secrets of getting rich in real estate and in fact, the only ones getting rich are the ones selling the courses. 

A lot of developers don't want you (or any potential competitors) to know their trade secrets and efficiencies, which they've taken years and maybe decades to master.....

Ok, here it is, I will broadcast my tripple-diamond "secret sauce" recipe: (A) exposure, Exposure, EXPOSURE.

And here's the dirty secret than lenders will not tell you:  the lender who you get the construction loan from DOES NOT have to be the lender you convert with.

Leverage is the secret sauce that makes real estate so attractive.  

Pretend to be a renter and secretly shop the competition. 

Contrary to what you've been told, there's no magic or secret to it.