Doubling mulling spices

Hi gang! I ordered a neat spiced winter ale from morebeer.com and it comes with some great spices, which are described as subtle,not overpowering. However, my buddies and I live in new england and we don't exactly do "subtle" when it comes to our winter brews. In fact, when we get a winter warmer and the spices don't reach out of the glass and punch us in the face, we are underwhelmed and disappointed. So, what I want do is double or possibly even triple (thats right,I said triple!) Those spices. I also plan on adding nutmeg the mix. Here is the kit....

http://morebeer.com/view_product/18413//Holiday_Christmas_Ale_-_Extract_Beer_Kit_

So my question, to the experienced brewers that appreciate a heavy spice bag, is this....

Would doubling or tripling the spices accomplish what I want (a strong spice aroma and flavor without compromising the integrity of the beer), or am I headed for disaster? Also, are regular household spices OK to use? Is there anything I should do to prepare them, such as soaking them in vodka or boiling them? I want a powerfully spiced beer, but more importantly, I want GREAT beer!

I thank you in advance for your help!

I've used spices in many brews and I can say with all certainty that much spice would be like dumping a spice rack in your mouth. If you want it strong I would only increase what comes with the kit by no more than 50% (Maybe 1/4-1/2 tsp each) and add them in the last 10 minutes of the boil.

If, after fermentation, you think it needs more, you can always "dry-hop" additional spices in the secondary or make an extract by mixing the spices with a bit of vodka on your brew day in a sanitized, sealed jar, leave it during your entire fermentation period, strain it and add it bit by bit to your bottling bucket or keg until you like what you have.

Kitchen spices are perfectly fine to use and much cheaper than what you would get at a LHBS.