Thank you for coming here. While this is not a DIY forum, you came to the right place.
Your friend is WRONG. What he suggests will only fool a cheap tester. It does not "ground" the receptacle; it makes whatever you plug in part of the 'neutral' wire. A fault anywhere in the house, and you will get shocked.
The correct solution is to find the first receptacle in the series, and replace it with a GFCI receptacle. The others can then be replaced with three-prong types.
The GFCI comes with little stickers that read 'no equipment ground.' Place one on each ungrounded three-prong receptacle.
Your receptacles will still not be grounded- and a plug-in GFI tester will not work.
The NEC allows use of GFCI's as a substitute form of protection in this situation.
Even though the tester will not work, the GFI function of the device will still work.
If you are using certain equipment, like some surge suppressors, that use a ground wire for normal operation.....they will still not work properly, and will need a new circuit run.
If you prefer, you may install GFI breakers in the panel, rather than GFCI receptacles. This may be preferred, especially if the house is old enough that the boxes are too small for the GFCI receptacle to fit.